A known wide format inkjet printing apparatus comprises a web supply unit for supplying a web from a roll in a process direction towards a printing station and a web tension control assembly for controlling tension of the web at the print station in the process direction. The print station comprises an inkjet print head assembly for applying droplets of ink on the web.
In case of processing a single web in a single mode, the single web is supplied by the web supply unit to the printing station and droplets of ink on the web are applied on the single web by the printing station. The web tension control assembly comprises an elongated member for guiding the single web, the elongated member extending in a direction being substantially perpendicular to the process direction. The web tension control assembly further comprises a first arm and a second arm for mounting said elongated member to a frame at a pivoting axis for pivoting the elongated member, and a tension mechanism arranged for applying a force on the elongated member to control the tension on the web in the process direction.
In case of processing two webs simultaneously, in this application also referred to as tandem mode, by the wide format inkjet printing apparatus, a first web and a second web are transported alongside one another towards the printing station. The first web and the second web typically have a total width in the transverse direction, which does not exceed the width of the printing station and does not exceed the width of the web tension control assembly. The first web and second web are tensioned in the process direction by the elongated member of the web tension control assembly.
A disadvantage of said web tension control assembly is that the first web and second web are tensioned dependently one another in the tandem mode.
Furthermore there is a desire for a compact structure of the web tension control assembly suitable for controlling tension of a single web in a single mode and for controlling tension of a first web and a second web independently one another in a tandem mode.